我的Spring Hibernate web应用程序在MySQL上运行，这给我带来了麻烦。
我四处搜索，尝试了不同的配置，在这个网站上读了不少帖子，但它仍然会露出微笑的头。
错误消息为：原因：com.mysql.jdbc.exceptions.jdbc4.CommunicationsException：从服务器成功接收的最后一个数据包是63313144毫秒前。最后一个成功发送到服务器的数据包是63313144毫秒前。比服务器配置的值"wait_timeout"长。在应用程序中使用之前，应考虑过期和/或测试连接有效性，增加服务器配置的客户端超时值，或使用连接器/J连接属性"autoReconnect=true"来避免此问题。
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 63,313,144 milliseconds ago. The last packet sent successfully to the server was 63,313,144 milliseconds ago. is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:408)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1137)
at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3965)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2578)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2758)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2820)
at com.mysql.jdbc.ConnectionImpl.setAutoCommit(ConnectionImpl.java:5359)
at net.sf.log4jdbc.ConnectionSpy.setAutoCommit(ConnectionSpy.java:764)
at com.mchange.v2.c3p0.impl.NewProxyConnection.setAutoCommit(NewProxyConnection.java:912)
at org.hibernate.engine.transaction.internal.jdbc.JdbcTransaction.doBegin(JdbcTransaction.java:72)
at org.hibernate.engine.transaction.spi.AbstractTransactionImpl.begin(AbstractTransactionImpl.java:162)
at org.hibernate.internal.SessionImpl.beginTransaction(SessionImpl.java:1435)
at org.hibernate.jpa.internal.TransactionImpl.begin(TransactionImpl.java:61)
at org.springframework.orm.jpa.vendor.HibernateJpaDialect.beginTransaction(HibernateJpaDialect.java:159)
at org.springframework.orm.jpa.JpaTransactionManager.doBegin(JpaTransactionManager.java:380)
... 46 more
Caused by: java.net.SocketException: Broken pipe
at java.net.SocketOutputStream.socketWrite0(Native Method)
at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:113)
at java.net.SocketOutputStream.write(SocketOutputStream.java:159)
at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82)
at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140)
at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3946)
... 58 more
MySQL的wait_timeout值为28800。
我的数据源，c3p0和Hibernate配置是：
@Bean
public DataSource dataSource() throws PropertyVetoException {
ComboPooledDataSource dataSource = new ComboPooledDataSource();
dataSource.setDriverClass(databaseProperties.getHibernateDriverClassName());
dataSource.setJdbcUrl(databaseProperties.getDataSourceUrl());
dataSource.setUser(databaseProperties.getDataSourceUsername());
dataSource.setPassword(databaseProperties.getDataSourcePassword());
dataSource.setAcquireIncrement(5);
dataSource.setMaxStatementsPerConnection(20);
dataSource.setMaxStatements(100);
dataSource.setMinPoolSize(2);
dataSource.setMaxPoolSize(5);
return dataSource;
}
@Bean
public LocalContainerEntityManagerFactoryBean entityManagerFactory() throws PropertyVetoException {
HibernateJpaVendorAdapter jpaVendorAdapter = new HibernateJpaVendorAdapter();
jpaVendorAdapter.setDatabasePlatform(databaseProperties.getHibernateDialect());
jpaVendorAdapter.setShowSql(true);
jpaVendorAdapter.setGenerateDdl(false);
Map<String, String> jpaPropertiesMap = new HashMap<String, String>();
jpaPropertiesMap.put("hibernate.dialect", databaseProperties.getHibernateDialect());
jpaPropertiesMap.put("hibernate.show_sql", "true");
jpaPropertiesMap.put("hibernate.format_sql", "true");
jpaPropertiesMap.put("hibernate.hbm2ddl.auto", databaseProperties.getHibernateHbm2ddlAuto());
jpaPropertiesMap.put("hibernate.transaction.factory_class", "org.hibernate.transaction.JDBCTransactionFactory");
jpaPropertiesMap.put("hibernate.ejb.naming_strategy", "org.hibernate.cfg.ImprovedNamingStrategy");
jpaPropertiesMap.put("hibernate.c3p0.min_size", "5");
jpaPropertiesMap.put("hibernate.c3p0.max_size", "20");
jpaPropertiesMap.put("hibernate.c3p0.timeout", "1000");
jpaPropertiesMap.put("c3p0.maxConnectionAge", "7200");
jpaPropertiesMap.put("c3p0.maxIdleTime", "7200");
jpaPropertiesMap.put("c3p0.unreturnedConnectionTimeout", "60");
jpaPropertiesMap.put("c3p0.debugUnreturnedConnectionStackTraces", "true");
jpaPropertiesMap.put("hibernate.c3p0.max_statements", "50");
// Prevent JPA from converting the dates to the UTC time zone
jpaPropertiesMap.put("jadira.usertype.autoRegisterUserTypes", "true");
jpaPropertiesMap.put("jadira.usertype.databaseZone", "jvm");
jpaPropertiesMap.put("jadira.usertype.javaZone", "jvm");
LocalContainerEntityManagerFactoryBean factoryBean = new LocalContainerEntityManagerFactoryBean();
factoryBean.setJpaVendorAdapter(jpaVendorAdapter);
factoryBean.setPackagesToScan("com.nsn.nitro.project.data.jpa.domain");
factoryBean.setJpaPropertyMap(jpaPropertiesMap);
String[] mappingsResources = new String[] {"custom/typedef.hbm.xml"};
factoryBean.setMappingResources(mappingsResources);
factoryBean.setDataSource(dataSource());
return factoryBean;
}
第二天早上，当我回到web应用程序时，整个晚上都没有访问它，就会出现错误。
我知道MySQL wait_timeout是MySQL在关闭连接之前等待再次使用连接的秒数。
这意味着我的web应用程序正在尝试使用MySQL端已过期并已关闭的连接，而我的web应用程序仍然认为这是一个有效的连接。
我想我应该在MySQL之前让我的web应用程序超时连接。这样，web应用程序就不会重用MySQL端已经超时和关闭的任何连接，因为web应用程序端的连接已经超时。
感觉我所有的c3p0配置都没有完成它的工作。
我正在使用以下堆栈：
MySQL mysql-5.6.14
mysql-connector-java 5.1.32
Spring 4.1.0.RELEASE
spring-data-jpa 1.6.2.RELEASE
Hibernate 4.3.6.Final
hibernate-jpa-2.1-api 1.0.0.Final
C3P0 0.9.2.1
我在配置中做错了什么？
还是我应该明确地关闭连接？
以下是我如何设置存储库：
public interface LanguageRepository extends GenericRepository<Language, Long> {
}
@Repository
@Transactional
public class GenericRepositoryImpl<T, ID extends Serializable> extends SimpleJpaRepository<T, ID> implements GenericRepository<T, ID> {
private EntityManager entityManager;
public GenericRepositoryImpl(JpaEntityInformation<T, ID> entityMetadata, EntityManager entityManager) {
super(entityMetadata, entityManager);
this.entityManager = entityManager;
}
public GenericRepositoryImpl(Class<T> domainClass, EntityManager entityManager) {
super(domainClass, entityManager);
this.entityManager = entityManager;
}
public EntityManager getEntityManager() {
return entityManager;
}
@Override
@Transactional
public T deleteById(ID id) throws EntityNotFoundException {
T entity = findOne(id);
if (entity != null) {
delete(entity);
} else {
throw new EntityNotFoundException("The entity could not be found and was not deleted");
}
return entity;
}
}
public class GenericRepositoryFactoryBean<R extends JpaRepository<T, I>, T, I extends Serializable> extends JpaRepositoryFactoryBean<R, T, I> {
protected RepositoryFactorySupport createRepositoryFactory(EntityManager entityManager) {
return new BaseRepositoryFactory<T, I>(entityManager);
}
protected static class BaseRepositoryFactory<T, I extends Serializable> extends JpaRepositoryFactory {
private EntityManager entityManager;
public BaseRepositoryFactory(EntityManager entityManager) {
super(entityManager);
this.entityManager = entityManager;
}
@Override
protected Object getTargetRepository(RepositoryMetadata metadata) {
return new GenericRepositoryImpl<T, I>((JpaEntityInformation<T, I>) getEntityInformation(metadata.getDomainType()), entityManager);
}
@Override
protected Class<?> getRepositoryBaseClass(RepositoryMetadata metadata) {
return GenericRepositoryImpl.class;
}
}
}
@NoRepositoryBean
public interface GenericRepository<T, ID extends Serializable> extends JpaRepository<T, ID> {
public EntityManager getEntityManager();
public T deleteById(ID id) throws EntityNotFoundException;
}
我看不到任何close（）方法在那里被实现或调用。我的代码中缺少什么？
编辑：添加了C3P0的日志记录。以下是输出：
2014-10-17 14:29:00,464 INFO [AbstractPoolBackedDataSource] Initializing c3p0 pool... com.mchange.
v2.c3p0.ComboPooledDataSource [ acquireIncrement -> 5, acquireRetryAttempts -> 30, acquireRetryDelay
-> 1000, autoCommitOnClose -> false, automaticTestTable -> null, breakAfterAcquireFailure -> false,
checkoutTimeout -> 0, connectionCustomizerClassName -> null, connectionTesterClassName -> com.mchan
ge.v2.c3p0.impl.DefaultConnectionTester, dataSourceName -> agvw3s958cggbnis1syx|1acb901, debugUnretu
rnedConnectionStackTraces -> false, description -> null, driverClass -> net.sf.log4jdbc.DriverSpy, f
actoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> false, identityToken -> agvw3s958c
ggbnis1syx|1acb901, idleConnectionTestPeriod -> 0, initialPoolSize -> 3, jdbcUrl -> jdbc:log4jdbc:my
sql://127.0.0.1:3306/nitroproject, maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, maxIdleTim
e -> 0, maxIdleTimeExcessConnections -> 0, maxPoolSize -> 5, maxStatements -> 100, maxStatementsPerC
onnection -> 20, minPoolSize -> 2, numHelperThreads -> 3, preferredTestQuery -> null, properties ->
{user=******, password=******}, propertyCycle -> 0, statementCacheNumDeferredCloseThreads -> 0, test
ConnectionOnCheckin -> false, testConnectionOnCheckout -> false, unreturnedConnectionTimeout -> 0, u
serOverrides -> {}, usesTraditionalReflectiveProxies -> false ]
2014-10-17 14:29:00,479 DEBUG [BasicResourcePool] incremented pending_acquires: 1
2014-10-17 14:29:00,480 DEBUG [BasicResourcePool] Starting acquisition series. Incremented pending_
acquires [1], attempts_remaining: 30
2014-10-17 14:29:00,480 DEBUG [ThreadPoolAsynchronousRunner] com.mchange.v2.async.ThreadPoolAsynchr
onousRunner@11dbedc: Adding task to queue -- com.mchange.v2.resourcepool.BasicResourcePool$Scattered
AcquireTask@1dd75ae
2014-10-17 14:29:00,481 DEBUG [BasicResourcePool] incremented pending_acquires: 2
2014-10-17 14:29:00,481 DEBUG [BasicResourcePool] Starting acquisition series. Incremented pending_
acquires [2], attempts_remaining: 30
2014-10-17 14:29:00,482 DEBUG [ThreadPoolAsynchronousRunner] com.mchange.v2.async.ThreadPoolAsynchr
onousRunner@11dbedc: Adding task to queue -- com.mchange.v2.resourcepool.BasicResourcePool$Scattered
AcquireTask@15083c7
2014-10-17 14:29:00,482 DEBUG [BasicResourcePool] incremented pending_acquires: 3
2014-10-17 14:29:00,483 DEBUG [BasicResourcePool] Starting acquisition series. Incremented pending_
acquires [3], attempts_remaining: 30
2014-10-17 14:29:00,483 DEBUG [ThreadPoolAsynchronousRunner] com.mchange.v2.async.ThreadPoolAsynchr
onousRunner@11dbedc: Adding task to queue -- com.mchange.v2.resourcepool.BasicResourcePool$Scattered
AcquireTask@fbbf1d
2014-10-17 14:29:00,511 DEBUG [GooGooStatementCache] checkinAll(): com.mchange.v2.c3p0.stmt.DoubleMaxStatementCache stats -- total size: 0; checked out: 0; num connections: 0; num keys: 0
2014-10-17 14:29:00,523 DEBUG [C3P0PooledConnectionPool] com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager@e38aca.acquireResource() returning.
2014-10-17 14:29:00,523 DEBUG [BasicResourcePool] trace com.mchange.v2.resourcepool.BasicResourcePool@ad2e72 [managed: 1, unused: 1, excluded: 0]
2014-10-17 14:29:00,523 DEBUG [BasicResourcePool] decremented pending_acquires: 2
2014-10-17 14:29:00,523 DEBUG [BasicResourcePool] Acquisition series terminated successfully. Decremented pending_acquires [2], attempts_remaining: 30
2014-10-17 14:29:00,521 DEBUG [BasicResourcePool] com.mchange.v2.resourcepool.BasicResourcePool@ad2e72 config: [start -> 3; min -> 2; max -> 5; inc -> 5; num_acq_attempts -> 30; acq_attempt_delay -> 1000; check_idle_resources_delay -> 0; mox_resource_age -> 0; max_idle_time -> 0; excess_max_idle_time -> 0; destroy_unreturned_resc_time -> 0; expiration_enforcement_delay -> 0; break_on_acquisition_failure -> false; debug_store_checkout_exceptions -> false]
2014-10-17 14:29:00,523 DEBUG [C3P0PooledConnectionPoolManager] Created new pool for auth, username (masked): 'ni******'.
2014-10-17 14:29:00,523 DEBUG [BasicResourcePool] trace com.mchange.v2.resourcepool.BasicResourcePool@ad2e72 [managed: 1, unused: 0, excluded: 0] (e.g. com.mchange.v2.c3p0.impl.NewPooledConnection@acde7c)
2014-10-17 14:29:00,524 DEBUG [GooGooStatementCache] checkinAll(): com.mchange.v2.c3p0.stmt.DoubleMaxStatementCache stats -- total size: 0; checked out: 0; num connections: 0; num keys: 0
2014-10-17 14:29:00,525 DEBUG [C3P0PooledConnectionPool] com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager@e38aca.acquireResource() returning.
2014-10-17 14:29:00,525 DEBUG [BasicResourcePool] trace com.mchange.v2.resourcepool.BasicResourcePool@ad2e72 [managed: 2, unused: 1, excluded: 0] (e.g. com.mchange.v2.c3p0.impl.NewPooledConnection@acde7c)
2014-10-17 14:29:00,525 DEBUG [BasicResourcePool] decremented pending_acquires: 1
2014-10-17 14:29:00,529 DEBUG [BasicResourcePool] Acquisition series terminated successfully. Decremented pending_acquires [1], attempts_remaining: 30
2014-10-17 14:29:00,525 DEBUG [GooGooStatementCache] checkinAll(): com.mchange.v2.c3p0.stmt.DoubleMaxStatementCache stats -- total size: 0; checked out: 0; num connections: 0; num keys: 0
2014-10-17 14:29:00,530 DEBUG [C3P0PooledConnectionPool] com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager@e38aca.acquireResource() returning.
2014-10-17 14:29:00,530 DEBUG [BasicResourcePool] trace com.mchange.v2.resourcepool.BasicResourcePool@ad2e72 [managed: 3, unused: 2, excluded: 0] (e.g. com.mchange.v2.c3p0.impl.NewPooledConnection@acde7c)
2014-10-17 14:29:00,530 DEBUG [BasicResourcePool] decremented pending_acquires: 0
2014-10-17 14:29:00,530 DEBUG [BasicResourcePool] Acquisition series terminated successfully. Decremented pending_acquires [0], attempts_remaining: 30
2014-10-17 14:29:00,562 DEBUG [GooGooStatementCache] checkinAll(): com.mchange.v2.c3p0.stmt.DoubleMaxStatementCache stats -- total size: 0; checked out: 0; num connections: 0; num keys: 0
2014-10-17 14:29:00,574 DEBUG [ThreadPoolAsynchronousRunner] com.mchange.v2.async.ThreadPoolAsynchronousRunner@11dbedc: Adding task to queue -- com.mchange.v2.resourcepool.BasicResourcePool$1RefurbishCheckinResourceTask@1fec09e
2014-10-17 14:29:00,574 DEBUG [GooGooStatementCache] checkinAll(): com.mchange.v2.c3p0.stmt.DoubleMaxStatementCache stats -- total size: 0; checked out: 0; num connections: 0; num keys: 0
2014-10-17 14:29:00,575 DEBUG [BasicResourcePool] trace com.mchange.v2.resourcepool.BasicResourcePool@ad2e72 [managed: 3, unused: 2, excluded: 0] (e.g. com.mchange.v2.c3p0.impl.NewPooledConnection@acde7c)
2014-10-17 14:29:00,575 DEBUG [NewProxyConnection] com.mchange.v2.c3p0.impl.NewProxyConnection@39069f: close() called more than once.
2014-10-17 14:29:02,260 DEBUG [BasicResourcePool] trace com.mchange.v2.resourcepool.BasicResourcePool@ad2e72 [managed: 3, unused: 2, excluded: 0] (e.g. com.mchange.v2.c3p0.impl.NewPooledConnection@acde7c)
2014-10-17 14:29:03,111 DEBUG [GooGooStatementCache] checkinAll(): com.mchange.v2.c3p0.stmt.DoubleMaxStatementCache stats -- total size: 0; checked out: 0; num connections: 0; num keys: 0
2014-10-17 14:29:03,112 DEBUG [ThreadPoolAsynchronousRunner] com.mchange.v2.async.ThreadPoolAsynchronousRunner@11dbedc: Adding task to queue -- com.mchange.v2.resourcepool.BasicResourcePool$1RefurbishCheckinResourceTask@146219b
2014-10-17 14:29:03,112 DEBUG [GooGooStatementCache] checkinAll(): com.mchange.v2.c3p0.stmt.DoubleM
axStatementCache stats -- total size: 0; checked out: 0; num connections: 0; num keys: 0
2014-10-17 14:29:03,113 DEBUG [BasicResourcePool] trace com.mchange.v2.resourcepool.BasicResourcePo
ol@ad2e72 [managed: 3, unused: 2, excluded: 0] (e.g. com.mchange.v2.c3p0.impl.NewPooledConnection@acde7c)
2014-10-17 14:29:03,262 DEBUG [DefaultListableBeanFactory] Returning cached instance of singleton bean 'org.springframework.transaction.config.internalTransactionAdvisor'
2014-10-17 14:29:03,285 DEBUG [DefaultListableBeanFactory] Finished creating instance of bean 'entityManagerFactory'
然后它循环输出：
2014-10-17 14:34:10,399 DEBUG [ThreadPoolAsynchronousRunner] com.mchange.v2.async.ThreadPoolAsynchronousRunner$DeadlockDetector@70b40a -- Running DeadlockDetector[Exiting. No pending tasks.]
2014-10-17 14:34:10,825 DEBUG [ThreadPoolAsynchronousRunner] com.mchange.v2.async.ThreadPoolAsynchronousRunner$DeadlockDetector@15e34e2 -- Running DeadlockDetector[Exiting. No pending tasks.]
2014-10-17 14:34:10,825 DEBUG [ThreadPoolAsynchronousRunner] com.mchange.v2.async.ThreadPoolAsynchronousRunner$DeadlockDetector@15e34e2 -- Running DeadlockDetector[Exiting. No pending tasks.]
我想这个问题的出现是因为数据库服务器在应用程序连接池仍有句柄的情况下终止了连接。通过使应用程序连接池上的超时时间比数据库服务器端的超时时间短，连接在被数据库服务器终止之前由应用程序连接库续订，从而避免了这个问题。我的MySQL数据库服务器有28800秒的超时等待，我的应用程序连接池C3P0有14400秒的超时等候。从服务器到客户端的超时等待链必须更短，这是有道理的。
向JDBC连接添加以下参数将解决您的问题：
testOnBorrow="true" validationQuery="SELECT 1" validationInterval="60000"